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You are here: Home / Archives for mycotoxins

Alternaria alternata as a cause of allergic diseases

Jackson Kung'u

Alternaria alternata Alternaria alternata is a fairly common indoor mould. In one study it was found in 87% of the homes examined. It is considered one of the most important fungal allergens. Alternaria alternata has been implicated as the cause of allergic diseases in people exposed to wood and sawdust during paper production in paper mills. It is regarded as the main cause of allergy and asthma in children aged 6–11 years.

It is known to produce over 70 various mycotoxins with tenuazonic acid being the most commonly known.

Do you have a mould question regarding Alternaria? Call us today at (905)290-9101.

Filed Under: Fungi Tagged With: Alternaria, fungal allergens, mycotoxins

What Are the Health Effects of Eating Mouldy Food and Feed?

Jackson Kung'u

Recently we received the following questions and comments. “Eating mouldy bread is discouraged. Where can I find the facts that prove this? Are there moulds that grow on bread that are harmless? Some of my patients that survived food shortages in The UK during World War II by eating mouldy bread and other foods insist that such fears about mould are unfounded”.

Rye bread contaminated with the mould Monascus ruber Why Is Eating Mouldy Food
Discouraged?

It is true that people may eat mouldy food without any harm. In many cases, children and adults who live on the streets in developing countries survive on food and fruits thrown into waste bins. Most of these foods and fruits are usually contaminated with mould and bacteria. The major reasons why eating mouldy food is dangerous is because such food is likely to be contaminated with mycotoxins (i.e., fungal poisons). Luckily, toxigenic moulds require certain growth conditions to produce the toxins and hence presence of these moulds on food does not necessarily mean the food contains mycotoxins. There is also a risk of food poisoning caused by bacteria such as Staphylococcus aureus, Salmonella, Clostridium perfringens, Campylobacter, Listeria monocytogenes, Vibrio parahaemolyticus, Bacillus cereus, and Entero-pathogenic Escherichia coli.

Read the whole article at http://www.moldbacteria.com/mold/what-are-health-effects-eating-mouldy-food-feeds.html.

Do you have a mould question? Call us at (905)290-9101

Filed Under: Fungi Tagged With: mouldy food, mycotoxins

Stachybotrys chartarum: is it deadly?

Jackson Kung'u

Stachybotrys chartarum, also known by an old name as Stachybotrys atra, is a cellulose degrading fungus commonly found in soil and on materials rich in cellulose such as hay, straw, cereal grains, plant debris, wood pulp, paper, and cotton. It produces a mass of wet spores sticking together giving the appearance of black pin-heads. The spores (referred to as conidia) are single-celled and ornamented. In indoor environment Stachybotrys thrives on wet cellulose containing material such as drywall and wallpaper. It is thus common in buildings with mechanical or structural defects that result to moisture damage or dampness. It has been isolated from very wet gypsum board/walls and wallpaper; asbestos building substitute; HVAC humidifier water and fans. Although Stachybotrys chartarum mainly survives as a saprophyte (i.e., by feeding on dead organic material), it has also been reported to cause root lesions on soybeans.

Why is Stachybotrys chartarum so feared?
The health effects attributed to Stachybotrys chartarum are controversial. It is generally agreed that Stachybotrys chartarum can potentially cause allergic reactions from inhaled spores and also poses the threat of mycotoxin poisoning. However, there is still a lot of debate as to whether this mould is the sole cause of various illnesses as reported in the literature. One of the recent disputed claims is the idiopathic pulmonary haemorrhage that resulted in deaths of infants in Cleveland, Ohio, USA in 1993-1994. The publicity of this incidence and that of mould related legal cases where Stachybotrys was mentioned has fuelled the public fear for this mould. The mould has been given various names such as “deadly toxic mould” and “deadly black mould”.

What is known about Stachybotrys chartarum and ill-health?
The first reports associating Stachybotrys chartarum with ill-health dates back to the 1930s. Horses and other animals fed with straw and grains in Ukraine and other parts of eastern Europe developed disease symptoms such as irritation of the mouth, throat, and nose; shock; dermal necrosis; a decrease in leukocytes; haemorrhage; nervous disorder; and death. Russian scientists, in 1938, conducted intensive studies and demonstrated that these symptoms were due to mycotoxins produced by Stachybotrys chartarum that had grown on the cellulose rich straw. The disorders were subsequently named stachybotryotoxicosis. There are reports of stachybotryotoxicosis in farm workers who handled contaminated straw. Recent studies have shown spores of Stachybotrys chartarum to contain high concentrations of highly toxic mycotoxins. As mentioned earlier, in 1993-1994, an outbreak of pulmonary haemorrhage in infants in Cleveland, Ohio,USA, was initially attributed to Stachybotrys chartarum. Although studies associating the outbreak with this mould were later reviewed and the reviewers found little evidence to associate the disease with Stachybotrys chartarum, there are still no studies to date to prove or disapprove this association.

Current knowledge about Stachybotrys chartarum

  • Stachybotrys chartarum appears to be a species complex.

Recent studies seem to suggest Stachybotrys chartarum consist of closely related individuals in which case it is a species complex. What exactly constitutes Stachybotrys chartarum still remains uncertain. Strains of moulds currently referred to as Stachybotrys chartarum are morphologically and biochemically highly variable. Recently what used to be referred to as Stachybotrys chartarum has been separated into one other distinct species and 2 other strains that were only different from each other by secondary metabolites profiles. The distinct species was named Stachybotrys chlorohalonata. Stachybotrys chartarum and Stachybotrys chlorohalonata require an experienced mycologist to differentiate. The uncertainty of what strains constitutes Stachybotrys chartarum may explain in part the current confusion concerning the health effects attributed to this mould.

  • Stachybotrys chartarum produces potent mycotoxins

Stachybotrys chartarum produces a number of potent mycotoxins including trichothecenes Roridin E, Verrucarin J, and Satratoxin H. Trichothecenes are capable of inhibiting the synthesis of DNA, RNA, and protein. These toxins are present on the spore surface, and therefore can be inhaled into the lungs. Studies have also shown that Stachybotrys chartarum trichothecenes can become airborne not only in association with intact spores but also with particles smaller than spores such as fungal fragments. It is, however, not known what level of mycotoxin must be present in the air to affect human health. There is still insufficient evidence supporting a causal relationship between symptoms or illness among building occupants and exposure to mycotoxins.

References
D. -W. Li, C. S. Yang (2005). Taxonomic history and current status of Stachybotrys chartarum and related species. Indoor Air, Volume 15 Issue s9 Page 5 – June 2005

B. Andersen, K. F. Nielsen, U. Thrane, M. Cruse, J. Taylor, and B. B. Jarvis(2003). Stachybotrys chlorohalonata, a new species from water-damaged buildings,” Mycologia 95, 1228-1237.

D. M. Kuhn and M. A. Ghannoum (2003). Indoor Mold, Toxigenic Fungi, and Stachybotrys chartarum: Infectious Disease Perspective. Clinical Microbiology Reviews, Jan. 2003, p. 144–172S. Li, G. L. Hartman, B. B. Jarvis, and H. Tak, A (2001). Stachybotrys chartarum Isolate from Soybean.” Mycopathologia, 154, 41-49.

Filed Under: Fungi Tagged With: mycotoxins, Stachybotrys atra, stachybotrys chartarum

Mould and food spoilage

Jackson Kung'u

Mould not only contaminates our air but also contaminate our food. As the mould grows on food it produces enzymes that break down the food resulting to spoilage. In addition to enzymes, some moulds such as Aspergillus flavus also produce mycotoxins onto the food. Ingestion of mycotoxin-contaminated food is fatal. Hundreds of people in developing countries die every year after consuming grains contaminated with mycotoxins.

Food spoilage due to mould includes off-flavours, mycotoxins contamination, discoloration, and rotting. Spoilage can occur either in the field or in storage. The water activity of the food determines the types of mould spoiling the food.

Moulds commonly found on cereals, nuts and their products.
Aspergillus candidus
Aspergillus flavus
Aspergillus glaucus
Aspergillus niger
Aspergillus ochraceus
Aspergillus parasiticus
Chrysonilia sitophila

Fusarium spp., e.g., Fusarium graminearum
Penicillium citreoviride
Penicillium citrinum
Penicillium expansum
Penicillium islandicum
Penicillium stoloniferum
Penicillium verrucosum
Rhizopus stolonifer

Moulds commonly found on high sugar foods.
Aspergillus glaucus
Penicillium corylophilum
Wallemia sebi

Moulds commonly found on fruits and vegetables.
Alternaria spp
Aspergillus niger
Botrytis cinerea

Cladosporium spp
Fusarium spp
Gloeosporium spp
Penicillium digitatum
Penicillium expansum
Penicillium italicum

Rhizopus stolonifer
Sclerotinia spp

Moulds commonly found on animal products such as meat, eggs, fish and milk
Aspergillus spp, e.g., Aspergillus versicolor
Eurotium spp, e.g. Eurotium herbariorum
Penicillium spp. e.g., Penicillium commune
Scopulariopsis spp.

Do you have a question on mould? Send it to My Question.

Filed Under: Fungi Tagged With: food spoilage, mould, mycotoxins

The Mould Stachybotrys chartarum: Why Is It So Feared?

Jackson Kung'u

The health effects due to the mould Stachybotrys chartarum are controversial. Stachybotrys chartarum, also known by an old name as Stachybotrys atra, is a cellulose degrading fungus commonly found in soil and on materials rich in cellulose such as hay, straw, cereal grains, plant debris, wood pulp, paper, and cotton. Although Stachybotrys chartarum mainly survives as a saprophyte (i.e., by feeding on dead organic material), it has also been reported to cause root lesions on soybean.

Why is Stachybotrys chartarum so feared?
The first reports associating Stachybotrys chartarum with ill-health dates back to the 1930s. Horses and other animals fed with straw and grains in Ukraine and other parts of eastern Europe were found to develop disease symptoms such as irritation of the mouth, throat, and nose; shock; dermal necrosis; a decrease in leukocytes; hemorrhage; nervous disorder; and death. Russian scientists, in 1938 conducted intensive studies and demonstrated that these symptoms were due to mycotoxins produced by Stachybotrys chartarum that had grown on the cellulose rich straw. The disorders were subsequently named stachybotryotoxicosis. Stachybotrys chartarum, conidiophores and spores as seen under a microscopeStachybotryotoxicosis has also been reported in farm workers who handled contaminated straw. Recent studies have shown spores of Stachybotrys chartarum to contain high concentrations of highly toxic mycotoxins. In 1993-1994 an outbreak of pulmonary hemorrhage in infants in Cleveland, Ohio,USA, was initially attributed to Stachybotrys chartarum. Since this incidence, this mould has received a lot of media attention in North America and has been given various names such as “toxic mould” and “black mould”. Although studies associating the outbreak with this mould were later reviewed and thought not to provide enough evidence to associate the disease with Stachybotrys chartarum, there are still no studies to date to prove or disapprove this claim.

Do you have a mould question? Send it to My Question.

Filed Under: Fungi Tagged With: mycotoxins, pulmonary hemorrhage, Stachybotrys atra, stachybotrys chartarum

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